Perovskite is one of the most common crystal
structures found on the planet. But common doesn’t mean boring. While it was originally discovered as a mineral, this amazing crystal shape shows up everywhere, and is a common subject, for cutting-edge scientific research. For starters, Earth scientists are fascinated with it, because even though it's the most abundant kind of mineral on the planet, We hardly ever see it. Most of it is buried deep within the earth’s mantle. Perovskites make up 93 percent of the lower
mantle’s mass, and 38 percent of the total mass of the planet. There are several different kinds of perovskite, but they share a similar, dense crystalline structure. In the mantle, silicate-perovskites are the
most common; the high density of these minerals create the sharp boundary at a depth of 660 kilometers that separates the less dense upper mantle, from the more dense, perovskite-rich lower mantle. Below 2600 kilometers, the pressure crushes, silicate-perovskites into a new mineral called post-perovskite. Post-perovskite is mechanically weaker, but
has a higher electrical conductivity that allows pockets of the mineral to interact
with Earth’s magnetic field. Researchers theorize that all terrestrial
planets bigger than Mars, have a similar abundance of perovskites deep beneath their surface, so mapping out these mineral transitions allows us to not only learn more about the internal structure of our planet, but other planets as well. Perovskite’s knack for conductivity brings
to the fore another quirk that makes it the perfect target for research. Metal-halide perovskites are a type of crystal
that can act as a semiconductor. So scientists are looking at how it can be
incorporated into various technologies. In 2009, researchers discovered that by shining
light on perovskite, they were able to induce a small electric charge, creating a minuscule solar cell. Since then, the efficiency of perovskite-based
solar cells has increased to over 22 percent. These panels generate electricity via a thin
layer of Lead halide perovskite film on top of a coating of conductive oxide. One of the benefits to using perovskites in
solar cells is their “defect-tolerance.” Unlike silicon cells, where everything has
to be aligned perfectly to work, and any damage renders the entire device unusable, perovskite cells can be simply layered onto a surface and generate an electric charge, making manufacturing easier and cheaper. But while engineers are hopeful that perovskite
could help to bring down the price of solar energy, they have some downsides for now. The perovskite cells are small, fragile, and
degrade much faster than conventional silicon crystal panels: on the order of hours and days, instead of years. If perovskite can take in light, could it
also make it? Researchers are looking into improving screens and LEDs, Using lead halide perovskites as “quantum dot” nanocrystals On a LCD TV screen, pixels are made up of
3 colors: red, green, and blue. Tests with prototype perovskite pixels used
a single kind of light source, blue LEDs, with perovskite/polymer beads on top to control
the color. When the blue light shines through the beads,
the color of the light that makes it through comes out in a green or red hue. While silicon quantum dot displays are out
on the market already, they are very expensive. So like solar panels, using halide perovskites could bring down the cost of manufacturing immensely. The colors created by this perovskite prototype, exceeded some television and computer monitor standards good enough for use in a future TV. Even though each of these uses has some roadblocks
to adoption, the massive increase in research and studies about perovskite means we’ll be seeing a lot of this crystal structure in the years to come.
